In U.S. Pat. No. 6,098,585, assigned to the assignee of the present invention, an internal combustion engine, which can be started from rest without benefit of a starter motor, is disclosed. Conventional engines are equipped with camshaft-actuated intake and exhaust valves. The camshaft or camshafts are gear or belt-driven from the engine's crankshaft. Thus, the camshaft position, and consequently the valve open/close status, is coupled to the crankshaft position. An engine at rest, therefore, has some cylinders with one valve open, some cylinders with both valves closed, and possibly one or more cylinders with both valves open. According to '585, a cylinder, or cylinders, with both valves closed and with the piston in the appropriate position, can be supplied fuel and ignited to initiate engine rotation.
The inventors of the present invention have recognized that an engine with intake and/or exhaust valves coupled to engine rotation, as described in '585, may have at best one cylinder in a favorable position for providing the fuel in the spark. The inventors have further recognized that engine in which the actuation of the valves is decoupled from the rotation of the engine allows control over valve position so that more cylinders can be fueled and ignited to initiate engine rotation more robustly.